"You've more than justified your selection I think Dreeko, but perhaps you've used up all your luck. Just one more decent hit before you go should do."
Kingdra: Flail - Flail - Flail
Kingdra used Flail! [10 EN]
Crit [625]: 5967 NO
(15-1.5)*1 = 13.5
Mr. Mime used Dazzling Gleam! [5 EN]
Crit [625]: 3329 NO
(8+3+1.5)*1.5 = 20.25
Kingdra was KO'd!
Handbook said:Substitutions based on knowing something can only trigger after that thing is known. (e.g if the opponent crits a2 then counter that action is legal if you were already going to move second a2, but illegal otherwise).